Posterization

Discussion in 'Alternative Processes' started by 2F/2F, Oct 29, 2010.

  1. 2F/2F

    2F/2F Member

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    Hello,

    I am having a hard time finding examples of analog monochrome posterization online. I am working on ideas for a screen print, and I am looking for a few examples to help me decide what to print. I have found a few examples of analog posterization using multiple colors, but none using tones alone.

    Also, if anyone has any experience with this process, I could use to ask a few questions. The most important is about the staggered pos/neg sandwiches, and whether or not they are necessary when printing with ink as opposed to on a light-sensitive surface like photo film or paper. It seems that I might be able to get away without doing the sandwiches if I print my lightest tones first.

    I would like to achieve an effect similar to these gorgeous National Park Service posters: http://www.fordcraftsmanonline.com/servlet/the-WPA-Posters/s/13/Categories. However, these were not done from photographs TMK.
     
  2. Rick A

    Rick A Subscriber

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    Find a copy of "Photographic Printing" by Ralph Hattersley. He covers posterization and negatives for screen printing in the book, as well as most other forgotten processes..
     
  3. 2F/2F

    2F/2F Member

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    Thanks, Rick. I had found a few books already, but this was not one of them.

    Even though there are some books for me to look into, I am interested to hear what the A.P.U.G. community has to offer about this technique.
     
  4. holmburgers

    holmburgers Member

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    Those WPA posters are really something else. A noble goal you have set for sure!

    I know that Andreas Feininger covers posterization, albeit briefly, in some of his books. Try 'the Complete Color Photographer' if you have easy access to it. Rick's suggestion is probably better though, just wanted to add my 2¢
     
  5. Bob Carnie

    Bob Carnie Subscriber

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    You know , I use to do this kind of work with E6 final film, using pos neg techniques . It has been over 22 years and my memory is not what it was.
    I will give this some thought look at the images and try to give you a working method of doing this.
    You will need a register punch, lith chemicals A B , line film or litho film, red ruby for masking , a vacumn contact frame. and a lot of patience.
    You could work to E6 , I do not think inter neg film is still out there, if it was you could image direct to colour neg and then make prints.
    The methods I used were for photographic colour paper and not ink so this may have a factor .

    I will let this thread go for awhile and try to see if I can give you the goods.

     
  6. Ian Grant

    Ian Grant Subscriber

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    Like Bob it's years since I did posterisations for personal work, I did do some for Album covers, posters etc ion the 80's.

    Essentially you need to make a series of lith negs of differing exposures, this gives the separation tones, if the original is a negative then you need to then make contact lith negs from the lith positives. It's remarkably easy to do. Some registration marks help enormously :D

    Ian
     
  7. 2F/2F

    2F/2F Member

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    Hello,

    Thanks for the replies.

    The final product will be an ink print done with screen stencils. I have studied a bit on the posterization process that is performed to make silver prints. It involves making a series of exposures from an original negative or positive, and processing them in a halftone developer (A/B). Then contacts are made to give you an opposite set. When you sandwich each pos/neg set, you, of course, get nothing but black. However, when you offset the second series from the first, you have transparent areas. Each offset sandwich is assigned a color or tone, and rephotographed in registration to make a single posterized negative from which the print is made. Filters are used when rephotographing to assign the colors for color prints, and neutral density is used when rephotographing to assign the tones in black and white prints.

    With light alone creating the various densities on the copy neg, it is, of course, necessary to provide a clean separation between each color or tone. Thus, the offset sandwiches would seem to be a necessity. However, since I will be contact printing the lithos onto screen emulsions, doing a separate screen for each layer of ink, and using opaque inks, it would seem that if I print my lightest tones first, the purposes of making the offset sandwiches would be reduced to 1) using less ink (since the lighter colors would require a lot of it if not using the offset sandwiches to expose the screens), and 2) making the overall thickness of the ink on the paper uniform.

    So, what I am really wondering is if I am right, and the offset sandwiching is not really necessary for layer-at-a-time ink print printed from lightest to darkest. Also, if I am right, and the print can be made without using sandwiches, I am also wondering if I should go ahead and use them anyhow for any particular reasons other than the two I mentioned above. The exactness of registration it would require when inking the prints might not be attainable with my current "rickety" work station. Using more ink and printing over lighter colors seems like it could help me cover the slop. Making a perfect edge match with a screen is extremely difficult due to the flexibility of the screens. Usually a slight overlap or "trap" is used where two tones or colors meet.

    Boy, do computer users have it easy! :D
     
  8. Steve Smith

    Steve Smith Subscriber

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    I have done this in the past but it was very much a trial and error process (mainly error). My method was a very basic version of Ian's and I think I only got to three tones with my experiments.

    If you are printing on the surface of the substrate then you are correct that you should print the lightest tones first. Just about everything I do now with screen printing graphics is printed to the rear of clear polyester - in which case the darkest ink is printed first.

    I would do it simply so that the darkest print is printed on top of the next lightest and so on. I wouldn't try to do it so that each area of tone had only one layer of ink as the registration would be nearly impossible to setup.

    These are front facias for membrane switch panels though, not colour separated artworks.

    We do have one product with a four colour process print but that is created by some other method which we don't talk about here!


    Steve.
     
  9. jeffreyg

    jeffreyg Subscriber

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    I can't help with the techniques described above. For what it may be worth (the last time I did any posterization was 35 years ago and they were gray scale) --- I used high contrast single weight paper and made paper negatives then either contact printed on to lith film or re-photographed and used the new negative in the enlarger. I used registration pins and a three-hole hole punch. It worked but it wasn't something I felt like taking any further.

    http://www.jeffreyglasser.com/
     
  10. Rick A

    Rick A Subscriber

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    Ralph Hatterleys book inspired me to do some screen printing, so I purchased a pile of gear from Dick Blick. I still havent gotten around to doing any printing, mainly a space(and time)problem. The chapter on photographic screen printing is fairly comprehensive on how to. I applaud you for wanting to do it the old-fashion method, I feel the end product will be reward enough for the effort involved.
     
  11. Bob Carnie

    Bob Carnie Subscriber

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    I see where you are going but I think I cannot help you, all my work was on film and I am not sure how it translates onto ink.
    Would love to see your results , once you get further down your crazy path.
    I am setting up to do my solarazations this weekend , I just counted the steps/chemical /wash - 22 to completion , so your pain is my pain.

    Bob
     
  12. richard ide

    richard ide Member

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    One thing you should consider when making your final positives for screen burning is to spread some of the images. I am sure I have read information on APUG but the method is easy. You expose your negative/positive with clear film between them and a diffuser such as matte surface drawing film on top. Use an increased exposure and the positive image will be larger than the negative. I have done spreads by contact with as much as 1/4" spread for large film for printing on difficult surfaces.
     
  13. Bob Carnie

    Bob Carnie Subscriber

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    We used a device called a Micro Modifier, much like a nuark plate burner which gave precise spreads and chokes. But as Richard states you will need to spread the film and then still re register for multiple printing.


    richard- got the strosser punch in US of A, give me a call.